Adaptive shift learn control for automatic transmissions

Abstract

An adaptive shift learn control system for rapidly updating an adaptive shift system that regulates shifting of a transmission includes first and second clutches and a control module that cycles the first clutch between an ON state and an OFF state while the second clutch is in a full OFF state. The control module monitors a parameter of the transmission during the cycling, calculates a clutch characteristic based on the parameter and updates the adaptive shift control system based on the clutch characteristic.

1. An adaptive shift learn control system for rapidly updating an adaptive shift system that regulates shifting of a transmission, comprising:
 first and second clutches of said transmission; and 
 a control module that cycles said first clutch between an ON state and an OFF state while said second clutch is in a full ON state, that monitors a parameter of said transmission during said cycling, that calculates a clutch characteristic based on said parameter and that updates said adaptive shift control system based on said clutch characteristic. 
 
     
     
       2. The adaptive shift learn control system of  claim 1  wherein said control module switches said first clutch between full ON and full OFF states. 
     
     
       3. The adaptive shift learn control system of  claim 1  wherein said control module ramps said first clutch between said ON and OFF states. 
     
     
       4. The adaptive shift learn control system of  claim 1  wherein said parameter includes a torque converter slip speed and said clutch characteristic includes a fill time of said first clutch. 
     
     
       5. The adaptive shift learn control system of  claim 4  wherein said fill time is determined based on a time between switching said first clutch to a full ON state and said torque converter slip speed increasing. 
     
     
       6. The adaptive shift learn control system of  claim 1  wherein said parameter includes a hydraulic pressure of said first clutch. 
     
     
       7. The adaptive shift learn control system of  claim 6  wherein said clutch characteristic includes an offset pressure of said first clutch. 
     
     
       8. The adaptive shift learn control system of  claim 7  wherein said offset pressure is equal to said hydraulic pressure at a point where a torque converter slip speed decreases while decreasing said hydraulic pressure. 
     
     
       9. The adaptive shift learn control system of  claim 6  wherein said clutch characteristic includes a full feed fill threshold pressure. 
     
     
       10. The adaptive shift learn control system of  claim 9  wherein said full feed fill threshold is equal to said hydraulic pressure at a point where a switch state of a pressure switch associated with said clutch switches to an ON state. 
     
     
       11. A method of updating adaptive shift learn set-points for regulating shifting of a transmission, comprising:
 cycling a clutch of said transmission between an ON state and an OFF state; 
 monitoring a parameter of said transmission during said cycling; 
 calculating a clutch characteristic based on said parameter; and 
 updating an adaptive shift control system that regulates shifting of said transmission based on said clutch characteristic, 
 wherein said parameter includes a torque converter slip speed and said clutch characteristic includes a fill time of said clutch, and wherein said fill time is determined based on a time between switching said clutch to a full ON state and said torque converter slip speed increasing. 
 
     
     
       12. The method of  claim 11  wherein said cycling includes switching said clutch between full ON and full OFF states. 
     
     
       13. The method of  claim 11  wherein said cycling includes ramping said clutch between said ON and OFF states. 
     
     
       14. The method of  claim 11  wherein said parameter includes a hydraulic pressure of said clutch. 
     
     
       15. The method of  claim 14  wherein said clutch characteristic includes an offset pressure of said clutch. 
     
     
       16. The method of  claim 15  wherein said offset pressure is equal to said hydraulic pressure at a point where a torque converter slip speed decreases while decreasing said hydraulic pressure. 
     
     
       17. The method of  claim 14  wherein said clutch characteristic includes a full feed fill threshold pressure. 
     
     
       18. The method of  claim 17  wherein said full feed fill threshold is equal to said hydraulic pressure at a point where a switch state of a pressure switch associated with said clutch switches to an ON state. 
     
     
       19. A method of updating adaptive shift learn set-points for regulating shifting of a transmission, comprising:
 engaging one of a plurality of clutches of said transmission to a full ON state to induce a tie-up condition of said transmission; 
 cycling another clutch of said plurality of clutches between an ON state and an OFF state; 
 monitoring a parameter of said transmission during said cycling; 
 calculating a clutch characteristic based on said parameter; and 
 updating an adaptive shift control system that regulates shifting of said transmission based on said clutch characteristic. 
 
     
     
       20. The method of  claim 19  wherein said cycling includes switching said another clutch of said plurality of clutches between full ON and full OFF states. 
     
     
       21. The method of  claim 19  wherein said cycling includes ramping said another clutch of said plurality of clutches between said ON and OFF states. 
     
     
       22. The method of  claim 19  wherein said parameter includes a torque converter slip speed and said clutch characteristic includes a fill time of said clutch. 
     
     
       23. The method of  claim 22  wherein said fill time is determined based on a time between switching said another clutch of said plurality of clutches to a full ON state and said torque converter slip speed increasing. 
     
     
       24. The method of  claim 19  wherein said parameter includes a hydraulic pressure of said another clutch of said plurality of clutches. 
     
     
       25. The method of  claim 24  wherein said clutch characteristic includes an offset pressure of said another clutch of said plurality of clutches. 
     
     
       26. The method of  claim 25  wherein said offset pressure is equal to said hydraulic pressure at a point where a torque converter slip speed decreases while decreasing said hydraulic pressure. 
     
     
       27. The method of  claim 24  wherein said clutch characteristic includes a full feed fill threshold pressure. 
     
     
       28. The method of  claim 27  wherein said full feed fill threshold is equal to said hydraulic pressure at a point where a switch state of a pressure switch associated with said another clutch of said plurality of clutches switches to an ON state. 
     
     
       29. A method of updating adaptive shift learn set-points for regulating shifting of a transmission, comprising:
 cycling a clutch of said transmission between an ON state and an OFF state; 
 monitoring a parameter of said transmission during said cycling; 
 calculating a clutch characteristic based on said parameter; and 
 updating an adaptive shift control system that regulates shifting of said transmission based on said clutch characteristic, 
 wherein said parameter includes a hydraulic pressure of said clutch, wherein said clutch characteristic includes an offset pressure of said clutch, and wherein said offset pressure is equal to said hydraulic pressure at a point where a torque converter slip speed decreases while decreasing said hydraulic pressure. 
 
     
     
       30. A method of updating adaptive shift learn set-points for regulating shifting of a transmission, comprising:
 cycling a clutch of said transmission between an ON state and an OFF state; 
 monitoring a parameter of said transmission during said cycling; 
 calculating a clutch characteristic based on said parameter; and 
 updating an adaptive shift control system that regulates shifting of said transmission based on said clutch characteristic, 
 wherein said parameter includes a hydraulic pressure of said clutch, wherein said clutch characteristic includes a full feed fill threshold pressure, and wherein said full feed fill threshold is equal to said hydraulic pressure at a point where a switch state of a pressure switch associated with said clutch switches to an ON state.